Abstract
A new bond auxiliary particle method for the Hubbard, t-J and Heisenberg Hamiltonians is presented. First, the one-dimensional (1D) Heisenberg Hamiltonian is studied as a test case. The exact ground state is approached rapidly via perturbation theory. At the level of second-order perturbation theory, the ground state energy is accurate within a few per cent, while in the 15th order it is accurate to five figures. Without any renormalization, the spin velocity is given with 10% accuracy, and the spectrum is correctly gapless. The degeneracy is also correct, giving a Wilson ratio R=2. The method is used to calculate analytically the full Green's function for a single hole in a half-filled (one electron per site) t-J model.
| Original language | English (US) |
|---|---|
| Article number | 012 |
| Pages (from-to) | 719-728 |
| Number of pages | 10 |
| Journal | Journal of Physics: Condensed Matter |
| Volume | 6 |
| Issue number | 3 |
| DOIs | |
| State | Published - Dec 1 1994 |
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics